Study of acquired color deficiencies using perimetric examination with reflecting chromatic targets as well as static and kinetic tests on the Tubingen perimeter with both achromatic and chromatic projected test targets. Psychophysical documentation of the course of untreated maculonathies in particular the senile choroidal form. Tests will include central field studies, measures of acuity, change in acuity with luminance and determination of the power of the magnification device required to maintain useful reading vision. Investigation of Read-Write closed circuit TV systems (1) as to their usefulness to those who must not only read but write, perform mathematical calculations etc.; (2) as to their value in group teaching of partially-sighted children. Ideal specifications will be determined for such devices to best meet the needs of users varying widely as to degree and type of visual impairment. Development of equipment and techniques for estimation of refractive errors when retinoscopy is impossible because of nystagmus lens opacities, etc.